The Biological Measures Core will provide the resources and expertise necessary to collect and analyze the hematological, neuroendocrine and cytokine indices for all research projects. This Core will create the requisite infrastructure and oversight to ensure the collection of reliable and high quality data through centralized testing and recordkeeping. Specifically, the Core will oversee the acquisition of specimens at the 3 regional General Clinical ResearchLaboratories, and direct the shipment of specimens to a central clinical laboratory in Madison, WI. It will also be the repository for the saliva samples from the diary studies to be used for assessing cortisol levels, and be the primary liason with the assay laboratory. Finally, the Core will maintain its own biochemical facility for the analysis of cytokine levels, and serve an archival function for the long-term storage of specimensfor the entire MIDUS program. In addition to assisting in the diagnostic testing, the Core will also be responsible for the creation of the data files of test results, and the dissemination of the information to primary investigators for each project. In this capacity, it will serve as the official repository for the paper records from all hematological and neuroendocrinetests, and will be responsible for all aspects of quality assurance, including assay reliability, data entry, and oversee any needed retesting of specimens. The Core will generate "reference norms" for all test results, both from the MIDUS as well as with respect to other studies and clinical laboratories, and thereby also serve a consulting role concerning the validity and meaning of the biological measures.